What happens when spark plug wires go bad?

Asked By: Pola Wegler | Last Updated: 18th April, 2020
Category: automotive road side assistance
4.7/5 (1,035 Views . 33 Votes)
The most common symptom of bad spark plug wires is a rough engine idle. Bad spark plugs wires can inhibit the normal flow of electrical current that reaches a vehicle's spark plugs, which can cause a rough, erratic engine idle.

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In this regard, do spark plug wires go bad?

Spark plug wires, sometimes called ignition cables, aren't as common as they used to be, but some cars made in the last couple decades still have them. If they go bad, your engine will likely suffer in terms of performance and fuel efficiency. A faulty spark plug wire can cause several problems: 1.

Furthermore, how long do plug wires last? If the vehicle is equipped with spark plug wires, they should be checked at the time of spark plug replacement. When they are old and crispy, just disengaging them from the spark plug can cause them to come apart. A quality set of spark plug wires can generally last around 60,000 to 70,000 miles.

Also Know, how often should spark plug wires be replaced?

That's why it pays to replace your spark plug wires before they wear out. We recommend changing them during spark plug changes (whenever your owner's manual recommends, usually between 60,000 and 100,000 miles).

How do I know if I need new spark plug wires?

Signs & Symptoms of Bad Spark Plug Wires

  1. Rough Engine Idle. The most common symptom of bad spark plug wires is a rough engine idle.
  2. Engine Miss. An engine miss, which normally occurs as the result of erratic or incomplete engine combustion, is another common symptom of bad spark plug wires.
  3. Engine Hesitation.
  4. Reduced Engine Power.
  5. Engine Surging.

25 Related Question Answers Found

How do you know if your coil pack is bad?

Common Symptoms of a Faulty Coil Pack
A rough idle. An unexplainably louder-than-usual engine. A blinking or intermittently activating check engine light. An active gas warning light when the vehicle has plenty of gasoline.

Can bad spark plug wires cause check engine light?

Worn spark plugs or spark plug wires can trigger your check engine light to come on. That's one reason your local Firestone Complete Auto Care offers FREE Code Scans, which will reveal any codes that indicate a misfire due to a spark plug failure.

What happens if one spark plug doesn't work?

Generally the plugs degrade over time, causing weak spark, poor combustion and reduced gas mileage. In most cases, a failure would cause a single cylinder to stop firing, causing strange engine sound and loss of power. Most newer cars will blink the check engine light if a spark plug suddenly fails.

Does changing spark plug wires improve performance?

Benefits of Spark Plug Wires
This could lead to misfires, a lower idle, and lack of power. Stronger and more durable cables hold the spark until it finds its way to the spark plug to boost the performance of your vehicle. Improve gas mileage. Running on bad spark plugs or spark plug wires can end up using more fuel.

How do you know when you have a bad distributor?


Here are some of the bad distributor cap symptoms you must know.
  1. Yelling Noises. Squealing noise from the car is the first sign of a bad distributor cap.
  2. Difficulty in Starting. Some of the bad distributor cap symptoms.
  3. Shaking.
  4. Stalling and Backfire.
  5. Difficulty Turning Over.

Are spark plug wires all the same?

All Spark Plug Wire Is Not The Same. There are four major types of spark plug wires but the only one safe to use with all street vehicles is carbon, high-resistance suppression wires. All spark plug wire is not the same.

What will bad spark plug wires do?

Bad spark plug wires can interfere with the electrical current flowing to the engine, making it difficult for the engine to complete the combustion cycle. An incomplete combustion cycle can cause an engine to misfire, which means your car may jerk, stumble, or briefly lose power.

Do new spark plug wires make a difference?

4 Answers. There isn't any performance to be gained from spark plug wires, just better build quality, which gives you not a better spark, but rather maintains an appropriate spark for more miles/years before their performance degrades to the point of needing replacement.

Can you change spark plugs without changing the wires?

It is not necessary to change the wires but it's a good idea. Here's the reason. If your spark plugs have been in the engine too long the component at the end of the plug get's oxidized over time from having such high voltage run across it to jump a gap and create a spark.

How do you check spark plug wires?


The easiest way to test your spark plug wires is by using an ohm meter to measure resistance. Look in the owner's manual to find the appropriate resistance for the wires. Then, pull the boot off of the spark plug and unscrew one of the wires at the end.

How do you check a spark plug coil?

Test the coil with a multimeter. Disconnect the coil pack's electrical connector then remove the coil pack from your car's engine using a wrench. Set the ohmmeter/multimeter to 200 ohms range then turn it on. Using a meter lead, attach the spark plug wire terminal to each coil.

Do spark plug wires add horsepower?

Spark plug wires can't add horsepower (despite what some may claim), but they can adversely affect your vehicle's performance. That's why it's important to select a good quality set of spark plug ignition wires to deliver juice to your spark plugs.

How long does it take to change spark plugs and wires?

Experts say the process can take anywhere from 30 minutes to 4 hours, depending on the vehicle. Ask your mechanic for an estimate before having the work done. Like many automotive components, Peck recommends staying with the original manufacturer's spark plugs when replacing them.

How often should ignition coils be replaced?

This part is used each time you try to start your engine, which is why it is so important that it remains repair free. The ignition coil on your car is supposed to last around 100,000 miles or more. There are a number of factors that can lead to this part become damaged prematurely.

How long do NGK Spark plug wires last?


Registered. Hello, Because NGK wires use a wire winding instead of a carbon core (like the OE wires) the resistance inside the wire will remain virtually the same for the life of the wires and so our wires can easily last over 100k miles so long as they are not damaged or contaminated.

Do you have to replace all spark plugs at once?

Luckily, spark plugs don't require replacement very often and can go years and many miles before replacement is a must. Most auto manufacturers suggest having new spark plugs installed about every 30,000 miles; however, spark plug longevity depends on the condition and type of spark plug.

How much do plugs and wires cost?

The average cost for a spark plug wire replacement is between $184 and $235. Labor costs are estimated between $88 and $112 while parts are priced between $96 and $123. Estimate does not include taxes and fees. When would you like to drop off your car?